Itaconic acid (or itaconate, depending on its prevailing ionization state; Medway, A. M., Sperry, Green Chem. 2014, 16, 2084-2101) and furfural (Cai, C. M., et al., J. Chem. Technol. Biotechnol. 2014, 89, 2-10) are two chemicals abundantly available from biomass. They are prominent entries on master lists of privileged compounds for potential use in preparing bio-sourced/sustainable/renewable polymers and materials (e.g., Ritter, S. K., Chem. Eng. News 2004, 82, 31-34; Top value added chemicals from biomass, Volume I-Results of screening for potential candidates from sugars and synthesis gas. eds. Werpy T., Petersen, G., US Department of Energy, 2004. nrel.gov/docs/fy04osti/35523.pdf (accessed Jan. 15, 2016)). The first arises by metabolic pathways as textbook as the citric acid (also known as the tricarboxylic or Krebs) cycle; the second by acid-catalyzed dehydration of 5-carbon sugars prevalent in, for example, corncobs (Adams, R., Voorhees, V., Organic Syntheses, Vol. 1, 1921, 49) and oat husks. For a century it has been known that each of itaconic anhydride (1, IA) and furfuryl alcohol (2, FA) is readily available by simple conversions such as dehydration (Fittig R., et al., J. Liebigs Ann. Chem. 1904, 331, 151-196) and reduction (Kaufmann W. E., Adams, R., J. Am. Chem. Soc. 1923, 45, 3029-3044) of these abundantly available precursors (Scheme 1).

The Diels-Alder (DA) [4+2] cycloaddition reaction to produce cyclohexene derivatives is among the most iconic of all reactions in organic chemistry. The ability of IA to function as a dienophile, the 2π-component, to engage various dienes was, in fact, described in the ground-breaking first publication by Diels and Alder (Diels O., Alder K., J. Liebigs Ann. der Chem. 1928, 460, 98-122). The use of furan as a diene, the 4π-component, was reported one year later in their second paper on the subject of “hydroaromatic synthesis” (Diels O., K., Ber. Dtsch. Chem. Ges. 1929, 62, 554-562). It appears that there have been no reports regarding the reaction of IA (1) or itaconic acid (or its esters) with any furan derivative in the intervening >85 years. A recent study of the DA reactions of 2-methyl- and 2,5-dimethylfuran with maleic anhydride, a more reactive, bio-derivable anhydride, has been reported (Mahmoud E., et al., Green Chem. 2014, 16, 167-175).
There is a continually growing interest in sourcing organic compounds from renewable resources. Compounds from renewable resources may be useful as such, or these compounds may be useful as intermediates to prepare other compounds or materials such as bio-sourced materials (e.g., polymers). The vast majority of plastics commonly used today (e.g., polyethylene and polystyrene) are produced from crude oil (petroleum) and natural gas. These plastics are widely used in applications ranging from automotive, packaging, adhesive, and construction materials.
However, because they are derived from non-renewable feedstocks, these are, necessarily, unsustainable materials. Alternatively, polymeric materials derived from renewable raw materials (e.g., sugars, cellulosics, vegetable oil, and terpenes) that have comparable properties to those of petroleum-derived polymers and plastics have the potential to meet the needs (and desires) of humans while having zero net impact on the earth's environment. Bio-soured plastics could find utility in essentially all of the myriad applications of today's plastics. Common chemical classes of polymers that can be bio-sourced include polyolefins, polyesters, polyamides, polyurethanes, and polycarbonates. Sustainable polymers or “green materials” can be both durable and degradable, they can be used in applications ranging from adhesives to packaging to clothing to building materials, and they can, in principle, be produced both economically and with minimal environmental impact.